Mixing and heat interchange apparatus



June 16, 1931. 55935 1,810,637

7 MIXING AND HEAT INTERCHANGE APPARATUS Filed April 1.2, 1929 S NTQR TTORNEY 'i Patented June 16, 1931 UNITEDSTATES PATENT OFFICE mm: mm or wnsrroar, CONNECTICUT, nssrenoa' are m 'runnoma conromrron, or new roan. n. Y, n conromrron or nnw Yonx Y with the heat-interchan I ma D HEAT INTERCHANGE APPARATUS Application filed April 1a, 1929. serial No. 354,403.

This invention relates to mixing and heatinterchange up ratus, and its principal object is to prov: e an im roved circulation of the material (called, or conyenience, the mix) in close proximity to or in contact surface, so that the heat-exchange is ma e more rapid and eficient.

To this end I provide, in conjunction with a jacketed tank, and mixing, or mix-circulating up aratus therein, one or more shields or shells ocated near thetank wall, and arranged to cause a lar part of the mix to move between the shie d and the tank wall. Since heat transfer is a function of the rate of flow at or ad'acent the thermal surface, the desired heat-interchan e is thus efiected in shorter time, and more e ciently, than has.

A. tank 1 has a jacket 2 with means for supplying or circulating a thermal (heating or cooling) medium therein, as suiiiciently represent by inlet connection 3 and discharge connection 4 as usual. In the tank, at the bottom, is any known or suitable mixing or material-circulating apparatus. As sho the mixer is a turbo-mixer of known t'ype, including a rotary impeller 5 which 'scha s material toward the tank wall.

In mixing ap aratus of this or similar es, as so far escribed, the material discharged from the impeller, or from a deilector which may be located about the impeller, moves in generally outward and upward directions toward the surface, returnent of any structures that are proping inward and downward generally adjacent the impeller shaft to the impeller intake; only a relatively small part of the mix moves in contact with, or close to the tank wall, and this movement may be undesirably slow, so that while the heat transfer through the metal wall, to or from the thermal medium in the 1acket, may be rapid and efiicient, the transfer between the mix and the thermal surface (inner surface of the tank) is slow and inefficient.

I therefore provide means for directing a major art of the mix in close proximity to the tan wall, as-follows:

A flow director is provided consisting of a shield, plate or shell 6, shaped to lie arallel to the tank bottom and side wal and spaced 9. suitable distance therefrom, and preferably terminating as at 7 a moderate distance above the tank bottom. Deflector blades 8, shaped and arranged to direct the mix (as discharged tangentially from the impeller) in radial directions or planes, are located between the shell 6 and the tank bottom (or a plate secured thereto) and may serve to support and space the shell from the tank bottom and wall. radial blades 9 may be located as shown, at or near the top of shell 6.

I also preferably provide another, or main, bafile shell or shield'lO, in cylindrical form, spaced moderately from the tank will, and having its lower margin 11 located within the upper margin of shell 6, and spaced therefrom. The main shield is supported in any suitable way; as by arms or struts 12 from the tank wall. The top of shieldlO is located a moderate distance below the normal surface-level of the mix.

In 0 eration, when the mix is at normal depth Fwith the tank normally full) material discharged from the impeller is confined between shell 6 and the tank bottom and wall, and flows outward and upward through the generally annular passage thus provided, and-then upward through the annular cylindrical space between the upper shield 10 and the tank wall, and then generally in ward and downward through the upper shield to the impeller intake. Practically Other vertical and all of the impeller material is thus caused to move in close proximity to the heated or chilled surface of the tank, with the increased efliciency of heat-transfer above referred to.

When. the mix is at a low level, say near or below thebottom of the upper shield 10, as indicated at the lower ri ht in Fig. 2, the impeller. provides simple cad to move it to the top of shell 6, over which it flows inward,'and then downward between shells 6 and 10, and so back to the impeller. The arran ment of lower and upper shields thus providzs for effective circulation when the material level is low; if this feature is not desired, the guard or shield may be made single and continuous, as by extending the cylindrical part of shelliG to the level of the top of shield 10, and omitting the latter.

"While as here shown, the lower shell or shield is arranged as a part of a deflector structure, an ordinary deflector of well known type may be placed about the 1mpeller, and the directing shield or shields arranged to receive material discharged from the deflector, and direct it in proximity to the tank wall, according to the principles above explained.

I claim:

1. In combination with a tank having a thermal jacket and material-circulating means within the tank, means 'for confining and directing a major part otfthe circulated material to flow in close proximity to the jacketed tank surface, said means including a shield spaced from the tank wall, and terminating at a moderate distance above t e tank bottom, and an upper, generally-cyli drical shield having its lower margin overlapping the upper margin of the shield first named, and spaced therefrom, and extending to a plane substantially above the upper edge of the shield first named.

2. In combination with a tank having a thermal jacket and material-circulating means within the tank, means for confining and directing a major part of the circulated material to flow in close proximity to the jacketed tank surface, said means including a shield spaced from the tank bottom and side wall, and having its lower portion positioned to receive material discharged from the material-circulating means, and terminating at a moderate distance above the tank bottom and an upper, generally-cylindrical shield having its lower margin overlapping the upper margin of the shield first named, and spaced therefrom, and extending to a plane substantially above the upper edge of the shield first named.

3. In combination with a tank having a thermal jacket and material-circulating means within the tank, means for confining and directing a major part of the circulated material to flow in close proximity to the jacketed tank surface, said means including a shield spaced from the tank wall, the shield 1 also having blades located between it and the tank wall and arranged to direct material flow in radial planes.

4. In combination with a tank havin a thermal jacket and material-circulating means within the tank, means for confinin and directing a major part of the circulate material to flow in close proximity to the jacketed tank surface, said means including a shield spaced from the tank wall, and terminating at a moderate distance above the tank bottom, and an upper, generally-cylindrical shield having its lower margin overlapping the upper margin of the shield first named, and spaced therefrom, and extending to a plane substantially above the upper edge of the shield first named, the lower shield also having blades located between it and the tank wall and arranged to direct material flow in radial lanes.

5. axing apparatus for circulating mate; rial repeatedly in a continuous circuitous course, comprising a tank having a thermal jacket, a rotary impeller, and a shield adjacent and spaced from the tank bottom, and side wall,'surrounding the impeller and extendingsubstantially upward from the tank bottom, providing a channel into which material is forced ,by the impeller and flows outward and upward in close proximity to the thermal jacket with increased heat exchange effect, and substantially upright blades between the shield and the tank wall, and adjacent the impeller, the blades being shaped and positioned to convert tangential movement of the material as discharged from the impeller to movement in radial and axial planes.

6. Mixing apparatus for circulating mate rial repeatedly in a continuous circuitous course, comprising a tank having a thermal jacket, a rotary impeller, and a shield adjacent and spaced from the tank bottom, and side wall, surrounding the impeller and extending substantially upward from the tank bottom, providing a channel into which material is forced by the impeller and flows outward and upward in close proximity to the thermal jacket with increased heat exchange effect, the material when carried in the tank at a low level flowing over the upper edge of the shield and downward toward the impeller axis for recirculation, and a second substantially cylindrical shield adjacent but spaced from the tank wall and having its lower margin within and spaced from the upper margin of the shield first named, the second shield extending up to a plane substantially above the upper edge of the first named shield, and acting when material is carried at a high level in the tank to direct material discharged from the passage between the first shield and the tank wall, upward from the tank bottom and side wall, sur- .60

adjacent the tank wall and then down within the second shield and toward the impeller axis for recirculation.

7. Mixing apparatus for circulating material repeatedly in a continuous circuitous course; comprising a tank having a thermal jacket; a rotary impeller in a low position in the tank, said impeller receivin material centrally and discharging it peripherally and tangentially adjacent the tank bottom; and a shield adjacent and spaced from the tank bottom and side wall, the shield surrounding the impeller and extending outwardly and upwardly therefrom thus providing an'annular channel into which material is forced by the impeller and flows outwardly and upwardly in close proximity to the bottom and side walls of the tank with increased heat exchange efiect.

8. Mixing apparatus for circulating'material repeatedly in a continuous circuitous course, comprising a tank having a thermal jacket, a rotary impeller in a low position in the tank designed to receive material centrally and having means to discharge it peripherally and tangentially adjacent the tank bottom, and a shield adjacent and spaced from the tank bottom and side wall, surrounding the impeller and extending substantially upward from the tank bottom, providing a circular channel into which material is forced by the impeller and flows outward and upward in close proximity to the thermal jacket with increased heat exchange effect, and substantially upright blades between the shield and the tank wall, and adjacent the impeller, the blades being shaped and positioned to convert tangential movement of the material as discharged from the impeller to movement in radial and axial planes.

9. Mixing apparatus for circulating material repeatedly in a continuous circuitous course, comprising a tank having-a thermal jacket, a rotary impeller in a low position in the tank designed to receive material centrally and having means to discharge it peripherally and tangentially adjacent the tank bottom, and a shield adjacent and spaced rounding the impeller and extending substantially upward from-the tank bottom, providing a circular channel into which material is forced by the impeller and flows outward and upward in close proximity to the thermal jacket with increased heat exchange effect, and a second substantially cylindrical shield adjacent but spaced from the tank Wall and having its lower margin within and spaced from the upper margin of the shield first named, the second shield extending up to a plane substantially above the upper edge of the first named shield, and acting when material is carried at a high level in the tank to direct material discharged from the first shield upward and adjacent the tank wall and then down within the second shield and toward the impeller axis for recirculation.

10. In combination; a tank havin means to control the temperature of the tan walls; a turbo-impeller positioned adjacent the bottom of the tank, said impeller being constructed to discharge material in an outward direction along the bottom of the tank; and means positioned adjacent the bottom and sides of the tank to' conduct the discharged material along the bottom and up the sides of the tank in close proximity to the tank walls.

11. In combination; a tank having means to control the temperature of the tank walls; a turbo-impeller positioned adjacent the bottom of the tank, said impeller being constructed to discharge material in an outward direction along the bottom of the tank; and means positioned adjacent the bottom and sides of the tank to conduct the discharged material along the'bottom and up the sides of the tank in close proximity to the tank walls, said means being provided with discharge areas at different levels above the tank bottom.

In testimony whereof I afiix my signature.

HENRY SANFORD BEERS. 

